Colorectal cancer has been commonly thought of as an old person’s disease. A new study however, highlights how this type of cancer (often called colon cancer for short) has escalated dramatically among children, teens, and young adults over the past two decades.

Results to be presented at Digestive Disease Week 2024, an international gathering of gastroenterology professionals, show a 500 percent increase in colon cancer cases among children ages 10 to 14 between 1999 and 2020.

In the same time frame, among teens aged 15 to 19, colon cancer has grown by 333 percent, while young adults aged 20 to 24 have seen a rise of 185 percent.

“Our findings were unexpected, given the historical perception of colorectal cancer as primarily affecting older individuals,” says lead researcher Islam Mohamed, MD, an internal medicine resident physician at the University of Missouri in Kansas City. “The notable percentage change is alarming, signalling a need to address and mitigate this trend.”

While the percentage shifts were remarkably high, Dr. Mohamed notes that the increase in the number of diagnoses was relatively low, and nearly 90 percent of all colorectal cancers continue to be diagnosed at age 50 and older.

An analysis based on data from the Centers for Disease Control and Prevention (CDC) revealed that colon cancer diagnoses rose by the following amounts between 1999 and 2020:

  • Among children 10 to 14 years old, cases rose from 0.1 to 0.6 cases per 100,000 children
  • Among teens 15 to 18, cases rose from 0.3 to 1.3 cases per 100,000 teens
  • Among young adults 20 to 24, cases rose from 0.7 to 2.0 cases per 100,000 adults

While the percentages are extremely small, this still equates to hundreds of thousands of cases of colon cancer among kids and young adults every year.

Experts Concerned About Rise in Early-Onset Colorectal Cancer

Still, many health authorities are finding the trend to be concerning.

“When I first started practice 30 years ago, there was literally nobody under the age of 50 with colon cancer – now flash forward a few decades and half my clinic is under the age of 50,” says John Marshall, MD, chief medical consultant of the Colorectal Cancer Alliance and director of the Ruesch Center for the Cure of Gastrointestinal Cancers at Georgetown University in Washington, DC.

“That’s a phenomenon we’re not only seeing here in Washington, DC, but also nationwide and even worldwide.”

In recognition of the rise of colorectal cancer cases among people under 50, in 2021 the U.S. Preventive Services Task Force lowered the recommended age to begin screening from 50 to 45 for average-risk adults.

What Are the Signs of Colorectal Cancer in Kids and Young Adults?

The study authors note that the number of colorectal cancer cases among children and teens is not high enough yet to suggest widespread routine colonoscopy screenings for that age group, although they may be warranted if young people show signs of cancer.

“Recognising symptoms of colorectal cancer is so important along with screening to detect earlier stage diagnosis and for a better outcome,” says Cathy Eng, MD, director of the Young Adults Cancers Program at the Vanderbilt-Ingram Cancer Center in Nashville, Tennessee, and a board member with Fight Colorectal Cancer.

If detected early on, this type of cancer is highly treatable and reduces the need for aggressive therapy.

Research published last year identified four warning signs to look out for:

  • abdominal pain
  • rectal bleeding, diarrhea
  • iron deficiency anaemia

Having just one of these signs was associated with nearly twice the likelihood of being diagnosed with early-onset colorectal cancer compared with having none of the signs. Three or more of these signs was associated with a 6 times greater risk.

“If you have symptoms, don’t delay an evaluation,” says Dr. Eng. “It could be your life or your child’s life at stake.”

Causes of Early-Onset Cancer Are Unclear

At this stage, what’s fuelling the increase in cancer at younger ages is a mystery. Dr. Marshall finds the trend puzzling because many of those diagnosed at his clinic have been physically fit. “We don’t actually know the answer to what’s going on,” he says.

The study authors, however, have identified some factors, including family history of inflammatory bowel disease or colorectal cancer, that may increase the chances of getting this type of cancer.

Certain modifiable habits may also raise the risk, including smoking and drinking alcohol, and eating a diet low in fibre and high in bad fats, processed meats, and sugar-sweetened beverages.

Not getting enough exercise, obesity, the presence of bacteria that tend to cause tumours, antibiotic usage, and food additives are also potential contributors to colorectal cancer risk, according to Mohamed and his colleagues.



Middle-Aged Adults Also Facing Higher Risk of Early-Onset Colorectal Cancer

Although the most striking percentage increases occurred among younger people, cases are also rising among middle-aged adults.

In the same two decades, colon cancer rose by 71 percent, to 6.5 cases per 100,000 people in adults aged 30 to 34, and by 58 percent, to 11.7 per 100,000, in those aged 35 to 39.

While the 40 to 44 age group had a comparatively lower percentage increase of 37 percent, it exhibited the highest case rate, with 20.0 cases per 100,000 people in 2020. (The study only looked at rates for people between ages 10 and 44.)

These additional findings further support evidence that colon cancer is affecting people at earlier stages of life than in the past.

“The trend that we are seeing in younger people is now extending even further down to a younger population, suggesting that whatever is causing this doesn’t take a lot of time to do its thing, so it increases the urgency for us to figure out what this problem is,” says Marshall.

SOURCE: Everyday Health